Tatsoi (Brassica narinosa or Brassica rapa var. rosularis) (塌棵菜, 瓢儿菜、乌塌菜, or 塌古菜 in Chinese), also calle spinach mustard, spoon mustard, or rosette bok choy, is an Asian variety of Brassica rapa grown for greens. This plant has become popular in North American cuisine as well, and is now grown throughout the world.